OBJECTIVES: The presence of antibodies against cyclic citrullinated peptides has been demonstrated to precede the symptom onset of rheumatoid arthritis (RA) by several years. Antibodies against 10 citrullinated autoantigen-derived peptides were analysed for reactivity before onset of symptoms. METHODS: In the Medical Biobank of Northern Sweden 409 individuals were identified, of whom 386 provided 717 samples, obtained before onset of symptoms of RA (median time 7.4 (IQR 9.3) years); 1305 population based controls were also identified. Antibodies to 10 citrullinated peptides; fibrinogen (Fib) Fibα573, Fibα591, Fibß36-52, Fibß72, Fibß74, α-enolase (CEP-1), Type II Collagen citC1(III) , filaggrin, vimentin (Vim)2-17, and Vim60-75 were analysed using a microarray system. RESULTS: The antibody fluorescence intensity of Fibß36-52, Fibß74, CEP-1, citC1(III) , and filaggrin was significantly increased in pre-disease individuals compared with controls (p<0.001). The levels of the earliest detectable antibodies (Fibα591 and Vim60-75) fluctuated over time, with only a slight increase after onset of disease. Antibodies against Fibß36-52, CEP-1 and filaggrin increased gradually reaching the highest levels of all antibodies before symptom onset. A cluster of antibodies, citC1(III) , Fibα573 and Fibß74 increased only slightly before onset of symptoms but prominently after disease onset. The odds ratio for development of RA with a combination of CEP-1 and Fibß36-52 antibodies (<3.35 years pre-dating) was 38.8 (CI95%14.5-103.5) compared with having either. CONCLUSION: Development of an immune response towards citrullinated peptides is initially restricted but expands with time to induce a more specific response with increasing levels towards onset of symptoms, particularly invoving antibodies against CEP-1, Fibß36-52 and filaggrin.
Wiley-Blackwell, 2013. Vol. 65, no 4, 899-910 p.